This invention relates to display devices, and in particular to display devices using phosphor materials capable of emitting visible light or ultra-violet radiation (UV) in response to electron or ion bombardment or UV radiation excitation.
The promise of High Definition Television (HDTV) can not be realized in the near future in spite of the recent breakthroughs and developments in the digital addressing and signal processing areas. Key factors such as high resolution, brightness, and flat-slim configuration associated with current TV displays remain to be resolved. A number of the problems associated with currently-available displays are described in detail in the papers referenced as [1], [2], and [3], whose identification appears in the annexed listing of references. Many of the principal limitations fall in the domain of phosphors. These imitations, specifically, saturation, low efficiency, degradation, prevent achieving the necessary brightness and simultaneous high resolution in currently used phosphors. For example, the blue phosphor presently used in Projection TV (PTV) saturates at excitation intensities which are significantly lower than those required for normal operation. In addition, all bulk phosphors degrade rapidly when HDTV-mode focussed electron beams are used. To fulfill the goal of HDTV in the next decade, phosphors are needed with improved properties in one or more of the following respects: efficiency, linearity at both low and high electron excitation voltages, and non-degradable over operating time.